Gridserve probably has the most comprehensive network out there at the moment covering major trunk roads. It's locations that they have yet to build into hubs are served by 2-3 50kw chargers in a single location, they can get busy. There are also normally alternatives just off the motorway too.
There are lots of big 'tesla style' charging hubs popping up all over the place from all the networks. While there not that many of them at the moment, they tend to be spread out all over the UK.
Being realistic, you probably will not be stopping at a location because you want to charge from that network, you'll be stopping there because its the right charger in the right location. I'm not at all fussed who provides it as long as its available, works and is in the right place (hopefully its fast too).
Most people consider the big networks to be:
Tesla
Gridserve
Instavolt
Shell Recharge
Ospray
BP Pulse
MFG
Pod Point (these are mostly slower AC posts but often very useful)
Other smaller networks of note which are building hubs around the UK:
Fastned (mostly in the EU around the Netherlands but have some hubs in the UK)
Ionity (plenty of fast UK sites but historically very expensive if you don't subscribe)
Apple Green (Welcome Break, new to the game but are adding their own branded chargers to their service stations)
Generally speaking all (except BP Pulse) are considered to be fine and any charge points put in within the last few years are pretty reliable. All of the old **** Ecotricity points on the motorway network(now taken over by Gridserve) have been swapped out for modern kit. Most of the above (Tesla, Pod Point and BP Pulse being the main exceptions) take card payment directly on the terminal.
As above, have a look at Zap Map and 'A Better Route Planner' check out your where to travel to and plan some routes. Charging at your destination, even if its off a 3-pin will make staying away from far more convenient. You can add a good amount of charge off a 3 pin overnight to get charged back up.
For home I'd certainly get a 'proper' 7kw plug put in so you can take advantage of time of use tariffs. Covering an average number of miles in an EV will double an average electric bill. If you can get that energy at 35p in the day and 7.5p for 4 hours overnight rather than 29p all the time, you'll save a big chunk of money (based on current prices). It generally doesn't work without a 'proper' 7kw plug because the car cant charge fast enough to take sufficient advantage of the 4 hour period at 7.5p.
